Pneumatic treating recovery head for dehydrated concentrates



April 4, 1939. A. K. ANDREWS 2,153,033

v PNEUMATIC TREATING RECOVERY HEAD FOR DEHYDRATED COCENTRATES Filed June 21, 1957 2 sheets-sheet A\1 INVENTOR //ber' ff. Hna/rews ATTORNEY'/ April 4, 1939.

A. K. ANDREWS 2,153,033l

PNEUMATIC TREATING RECOVERY HEAD FOR DEHYDRATED CONCENTRATES Filed June 2l, 1957 2 Sheets-Sheet 2 /o INVENTOR Hlber' T. 'ndrews ATToRNEY Patented Apr. 4, 1939 UNITED STATES PNEUMATIC TREATIN G vRECOVERY HEAD FOR DEHYDRATED CONCENTRATES Albert K. Andrews, Vancouver, Wash.

Application June 21,

7 Claims.

My device relates to a device to be used for the recovery of precious metal concentrates of high specific gravity that are contained in a free state in dehydrated materials. The device is particularly useful in arid placer mining properties where water is scarce and where the recovery of the precious metal is to be carried on in a dry state.

The concentrate being developed in any suitable recovery devices and methods are dehydrated and are then delivered to my device for the iinal recovery of the precious metal concentrate of high speciiic gravity from the remainder of the concentrated material.

The primary purpose and object of my invention consists in providing a simply constructed device that is comprised of few parts and which may be used for recovery of the precious metal of high specific gravity from the concentrate that is to be delivered into the device as a batch or as a 2O continuous feed.

A still further object of my invention consists in so constructing the device that it will be comprised of few parts and one that may be used with slight expenditure of power and one that may be successful-in the recovery of articles of different specific gravities and Where the same is tc be used as a batch recovery device or where the same is to be used in the continuous use and separation of the materials of high specic gravity I from those 0f lesser specific gravity.

With these and incidental objects in view, the invention consists in certain novel features of construction and combination of parts, the essential elements of which are set forth in the appended claims, and a preferred form of embodiment of which is hereinafter shown with reference to the drawings which accompany and form a part of this specification.

In the drawings:

Fig. 1 is a fragmentary sectional front view of the assembled device.

Fig. 2 is a fragmentary sectional side view of the assembled recovery head.

Like reference characters refer to like parts throughout the several views.

My device is comprised primarilyof a cylindrical treating recovery head I. The recovery head is removably positioned upon a flanged bushing 2. The flanged bushing 2 is threadably secured to a base 3. The base 3 is in communication with a source of flexible fluid under pressure and the same is connected thereto by any suitable pipe 4.

`In order that the velocity and pressure of the treated fluid to be delivered into the interior of the base 3 may be predetermined, a valve 5 is dis- 1937, Serial N0. 149,430

posed within the pipe 4 and the hand manipulation of the valve is accomplished by having a hand wheel 6 secured to and disposed upon the valve stem l.

'I'he concentrate to be treated is placed within the treating head I. A piston 8 is movable within the treating head I and it reciprocates longitudinally thereof. The movement of the piston is accomplished by the placing of a piston rod S below the piston 8 and I secure the same thereto by any suitable connecting wrist pin It. The piston rod 9 extends below the base 3 and the same is enclosed within any suitable tube I0 that extends below the base 3 and about the piston rod 9. A removable head I I is disposed upon the lower end of the tube I 0. A rack I2 is disposed upon one side of the piston rod 9 and a pinion I3 coacts with the rack I2 and the piston rod is moved longitudinally of the treating head by the rotating of the pinion I3, which is accomplished by securing the pinion I3 to a shaft I 4. The shaft I4 is rotated by any suitable hand crank.

I have found this may be successfully accomplished by the placing of a hand crank I5 upon the outer end of the shaft I4 to thereby facilitate the movement of the piston within the treating head I. A piston head I5 is threadably secured to the piston 8 vand a gasket I'I is disposed upon the outside of the piston head I6 and forms a relatively tight working relationship between the piston I6 and the inner wall of the treating head I. The piston head I6 has a iiange I8 inwardly extending from its top end and the top surface I9 of the piston head is downwardly and inwardly sloping.

A loosely woven fabric sheet 20 forms a top for the piston and the fabric sheet is clamped between the flange I8 of the piston head and the piston.

Where the treating head I is made of substantial diameter I provide a supporting bracket 2| Within the piston and a supporting pad 22 is disposed upon the free end of thebracket 2|. The top surface of the pad 22 is disposed central of the piston and terminates substantially below the top end of the piston 8. To this bracket the fabric sheet 20 is secured. by-any suitable fastening means as through the use of a set screw 23. This provides a cross diaphragm for the piston and a support for the concentrate to be treated that is placed within the treating head I.

The fabric sheet should be made suiiciently porous to permit the treating fluid as air to pass therethrough and it should be suiiiciently strong to support the concentrate material that is to be placed thereupon and within the treating head.

In the use of my device after the batch has been placed in the treating head I place a hood 24 upon the treating head I. The hood 24 is made frusto-conical and a flange 25 is disposed upon the base of the frusto-cone. A base pocket 26 is provided having a flange 21 terminating its upper outer periphery to facilitate the flanges 25 and 21 being placed in contact with each other and for being secured together with a relatively air tight i'lt.

The interior of the hood 24 is made substantially larger in cross sectional area than the treating head I. It is made larger in order that the velocity of air passing through the treating hood will be substantially less than the velocity of the air passing through the treating head I.

As air is admitted into the treating head I in sufficient volume to eect the recovery the velocity of the air raises the material of low specific gravity of theprecious metal concentrate disposed within the treating head appears to boil. The piston head assembly is then raised within the treating head I and the materials of low specific gravity flow over the top of the piston and those of high specific gravity gravitate to the bottom of the treating head I and rest upon the fabric sheet 20 and the materials of lesser specific gravity flow outward over the upper end 28 of the treating head I and into the receiving pocket 29.

A port 33 is disposed in the upper end of the hood 24 which permits the air and the fine dust particles to flow outward therethrough into normal air, or into other recovery bins that may be placed thereabove.

A skimming head 3I is disposed upon the lower end of a rod 32. The rod 32 passes through spaced aligned bearing supports 33 and 34 that maintains the same in alignment and the longitudinal center line of the rod 32 and of the piston rod 9 are common.

A rack 35 is disposed upon the rod 32 and a pinion 36 coacts with the rack 35. Longitudinal movement is imparted to the rod 32 and to the skimmer head 3I by securing the pinion 36 upon a shaft 3'I. A hand wheel 38 is disposed upon the outer end of the shaft 31.

A transparent block 39, preferably made of clear glass is disposed upon the lower end of the skimmer head 3I and a sloping surface 40 is disposed upon the lower surface of the block 39. The sloping surface 49 of the block 39 and the sloping surface I9 of the piston are similar in slope so that as the skimmer head and the piston rod approach each other a greater velocity may be imparted to the air passing between the respective sloping surfaces of the block 39 and the piston I8.

In the use of my device I make the fabric sheet 20 of wool felt or silk and since the air passing through the felt or silk and the agitation of the concentrate being treated sets up a certain amount of friction, it is believed that an electrically charged area is set up within the treating head I and at a point between the block 39 and the top of the fabric sheet to thereby aid in the recovery and the concentration of fine metal particles within the electrically charged area. Through the use of my device extremely ne particles of precious metal are recovered and it is believed that the electrified area is one of the controlling reasons.

In order that the interior of the assembly may be lighted during the carrying out of the recovery I place an electric light 4I within the hood and the same is energized by electricity flowing through electric conductors 42 that lead to a source of electric energy, not here shown.

The hood assembly 24 may be freely removed from the treating head I to remove the waste materials gravitating therethrough and remaining therein as the treating process progresses and it also facilitates the recovery of the precious metals remaining upon the fabric sheet after the charge has been treated and it also facilitates the placing of the added charges within the treating head I when the same is being carried on as a batch. Where the device is to be used in the continuous treatment of concentrates the base 29 may be emptied through the discharge outlets 42 that are positioned at one or more points within the base of the pocket 29.

A cut-off valve 43 is disposed within each of the .discharge outlets 42. A filler pipe 44 leads from a hopper 45 disposed upon the outside of the hood 24 and a tube 46 extends through the walls of the hood 24 and deposits concentrate material within the treating head I.

The refining of the concentrate may be carried on by the raising and lowering of the piston head fabric sheet Within the treating head I.

When the nal recovery is to be made the screen head I3 is lowered and at this time the tube 43 is drawn to one side to facilitate the skimmer head approaching that of the piston head and the fabric sheet disposed within the piston assembly. At suc-h times practically all of the undesirable foreign matter may be blown from the treating head and the recovery of the precious metal may be made substantially cornplete and free of dross material.

While the form of mechanism herein shown and described is admirably adapted to fulfill the objects stated, it is to be understood that it is not intended to confine the invention to the embodiment herein shown and described, as it is susceptible of embodiment in various forms, all coming within the scope of the claims which follow.

What I claim is:

l. In a device of the class described, in combination in a treating head, comprising a cylinder, a piston having a fabric diaphragm extending thereacross reciprocably disposed within the cylinder, manually manipulative means for imparting movement to the piston within the cylinder, a base, a bushing secured to the base and means for securing the bushing to the cylinder, means for conducting a compressible fluid into the base and below the piston, and through the cylinder, a frusto-conical hood removably securable to the top end of the cylinder, a venting port disposed in the top end of the hood and a receiving pocket formed integral with the hood and disposed at the bottom of the hood.

2. In a device of the class described, in combination, a treating cylinder normally open at its top end, a Sleeve reciprocably disposed within the treating cylinder, a diaphragm carried by the sleeve and disposed transversely of the treating cylinder, said diaphragm being sufficiently dense to support concentrate material thereupon and being suiciently porous to permit air in volume and innsity to pass therethrough to agitate and concentrate and to cause the concentrate material of low specific gravity to flow out of the treating cylinder as the diaphragm is moved toward the open end of the treating head and to retain the articles cf high specific gravity thereupon, means for delivering air under pressure into the base of the treating cylinder, and a ported hood removably attachable to the upper end of the treating cylinder and said hood having a pocket disposed within its base for retaining in its pocket materials flowing from the treating cylinder into the hood, and means for delivering materials into the top of the treating cylinder.

3. A device for recovering precious metal from a dried concentrate comprised of an open ended treating cylinder, a porous diaphragm movably disposed within the treating cylinder, means for admitting a controlled amount of compressed air within the base of the treating cylinder and below the diaphragm, means for reciprocating the diaphragm, a hood removably disposed upon and secured tothe treating cylinder, a port communicating the interior of the hood with the exterior, and a skimmer head adjustable relative to the open end of the treating cylinder and mounted within the hood.

4. In a device of the class described, the combination of a treating cylinder, a piston reciprocably disposed within the treating cylinder, manually manipulative means for moving the piston longitudinally of the treating cylinder, a fabric diaphragm disposed within the piston, means for supporting the diaphragm transversely of the piston and below the head of the piston, a base depending from the treating cylinder, means for conducting a compressible fluid into the base and below and through the fabric diaphragm, a frusto-conic-al hood superposed the treating cylinder and removably securable thereto, a venting port carried by the frusta-conical hood, a skimmer head carried by the hood having a longitudinal center line common to that of the longitudinal center line of the treating cylinder, means for moving the skimmer head toward and away from the top end of the treating cylinder and within the hood, and a pocket disposed within the base of the frusto-conical hood, and means for admitting materials through the walls of the hood into the treating cylinder.

5. In a device of the class described, the ccmbination of a treating cylinder, a piston reciprocably disposed `within the treating cylinder and adapted for being moved longitudinally of the treating cylinder, means for imparting longitudinal movement to the piston within the treating cylinder, a hood removably sec-ured to the treating head, a skimming head disposed within the hood, means for moving the skimming head toward and away from the open end of the treating cylinder, means for venting the hood and a pocket disposed within the base of the hood, and means for feeding material through the wall of the hood and into the treating cylinder.

6. In a device of the class described, the combination of a treating cylinder, a porous diaphragm reciprocably disposed within the treating cylinder, means for admitting air under pressure within the base of the treating cylinder and below the porous diaphragm, means for regulating the amount of compressed air to be passed through the porous diaphragm, a hood removably secured to the treating cylinder and a pocket disposed Within the base of the hood, and means for continuously admitting materials to be treated into the top end of the treating cylinder.

7. In a device of the class described, the combination of a normally open ended treating cylinder, means for admitting concentrate materials to be treated into the treating cylinder, a diaphragm adjustably disposed within the treating cylinder, said diaphragm being suiciently compact to support finely comminuted materials of high specic gravity thereupon and sufficiently porous to permit air to iiow therethrough in volume and velocity suiiicient to cause materials of low specific gravity to flow from the open end of the treating cylinder as the diaphragm is moved toward the discharge end of the treating cylinder, a venting hood having a pocket disposed within its base removably secured to the treating cylinder and an adjustable skimmer cylinder carried within the venting hood, and means for continuously feeding materials to be treated into the treating cylinders.

ALBERT K. ANDREWS.

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